A development has been progressing to attain a finer and a higher integration of a semiconductor device typified by a silicon semiconductor, depending on market needs for higher performance, compact sizing and the like. Accompanying with the finer and the higher integration, such a semiconductor substrate has been required that has a damascene interconnect which is capable of correspond to a fine wiring pattern. Usually, as for the damascene interconnect, copper, an aluminum alloy or the like is used as a wiring material, and titanium, titanium nitride, tantalum, tantalum nitride or the like is used as a barrier metal material.
In formation of such a damascene interconnect, a CMP process is carried out for planarization of the surface of a substrate (a wafer) having, for example, a metal wiring film, a barrier metal, an insulating film or the like, by using polishing slurry containing fine polishing particles, for example, silica, alumina and the like. In the CMP process, fine polishing particles, such as silica, alumina and the like, to be used in the CMP process, a wiring metal film polished, metal impurities (metal residues) derived from a barrier metal or the like, tend to remain at the surface of a semiconductor substrate (a wafer) after polishing. These residues influence adversely on electric characteristics of a semiconductor, such as short circuit between wirings, therefore as a post-process of the CMP process, a cleaning process is carried out to remove these residues from the surface of the semiconductor substrate (the wafer).
On the other hand, in carrying out the CMP process, suppression of generation of polishing residue of the metal wiring film, scratch or dishing, or the like is carried out, while preventing excessive polishing of the wiring film, by adding, for example, benzotriazoles (hereafter they may be abbreviated as BTAs), to form a coating film (a protecting film) containing an anticorrosive such as BTA or the like at the surface of the metal wiring film. Such a coating film (a protecting film) is necessary to be removed finally, in the manufacturing process of the semiconductor substrate, therefore, recently removal of residues of fine polishing particles (particles), metal impurities (metal residues) or the like is carried out at the cleaning process after the CMP process, as well as removal of these coating films is also carried out.
As the cleaning agent after CMP to be used in such a cleaning process, there have been known conventionally a cleaning solution containing at least one kind of an organic alkali (for example, PATENT LITERATURE 1), a cleaning agent for a substrate, containing an organic acid having at least one carboxyl group and/or a chelating agent, and a specific organic solvent (for example, PATENT LITERATURE 2), a cleaning agent for a copper wiring, containing a copper corrosion suppressing agent and water (for example, PATENT LITERATURE 3), a cleaning composition for a semiconductor workpiece, containing a ammonium hydroxide compound, a chelating agent and an anticorrosive compound (for example, PATENT LITERATURE 4), an alkaline aqueous cleaning composition, containing at least one kind of an amine and at least one kind of a deactivator (for example, PATENT LITERATURE 5), a cleaning agent for a copper wiring semiconductor, containing a quaternary ammonium hydroxide, an amine and the like (for example, PATENT LITERATURE 6), a cleaning composition, containing at least one kind of a solvent, at least one kind of an anticorrosive and at least one kind of an amine (for example, PATENT LITERATURE 7), a cleaning agent for a copper wiring semiconductor, containing a specific cyclic (poly)amine and a polyphenol-type reducing agent having 2 to 5 hydroxyl groups (for example, PATENT LITERATURES 8, 9), a cleaning agent for a copper wiring semiconductor, containing a specific amine, a specific polyphenol compound and the like (for example, PATENT LITERATURE 10), a cleaning agent for a copper wiring substrate, containing a specific amino acid and an alkylhydroxylamine (for example, PATENT LITERATURE 11) or the like.
In recent years, a development has been progressing to attain a still finer wiring, and there has been required a thin film-type barrier metal, accompanying with the finer wiring. However, titanium or tantalum, which has conventionally been used as a barrier metal, is difficult to prepare a fine thin film, and has been known to deteriorate barrier characteristics for preventing diffusion of a metal of a wiring material, caused by making a thin film. Accordingly use of metallic cobalt has been investigated as a new barrier metal material (for example, PATENT LITERATURE 12).